a. Field of the Invention
The present invention relates generally to retractable coverings for architectural openings and, more particularly, to an improved easy to manipulate wand for adjusting such coverings.
b. Description of the Relevant Art
Retractable coverings for various architectural openings such as windows, doorways, archways, and the like typically include a retractable barrier which might be a drapery, miniblind, vertical blind, or the like. Such retractable coverings have control systems that may be operated by pull cords or wands with wands typically being used in coverings having vertical or horizontal vanes or slats which are tilted or pivoted about their longitudinal axes by rotation of the wand.
The use of wands in coverings for architectural openings are desirable in that they avoid problems associated with endless loop cords such as children having body parts caught in the cord. Of course, with wands, accidents of this type cannot happen but wands have the disadvantage of sometimes being difficult to manipulate by individuals with arthritis or other infirmities in their hands. Wands are typically of a small diameter (less than 1/2") and since they must be rotated about their longitudinal axis, the operator of the covering of necessity needs to grip a relatively small rod and rotate that rod with the use of the fingers which becomes increasingly difficult with age.
Attempts to overcome the aforenoted problems are evident in several patented references such as U.S. Pat. No. 4,759,398 issued to Renee. The patent to Renee discloses an operating system for a venetian blind wherein a wand is made of an extruded synthetic resin and is, by way of example, hexagonal in cross section. The wand has been caused to assume a helical shape so that all six surfaces of the wand are helical. An operating element is slidably disposed on the wand and includes a portion that interfaces with the helical faces of the wand so that upon linear sliding movement of the operating element along the length of the wand, the wand is caused to rotate thereby negating the necessity of an operator having to twist the wand. A drawback with the system disclosed in the Renee patent resides in the fact that the entire length of the wand is helical and the control element slides along the total length of the wand which may be an undesirable feature of the system from an expense and aesthetic standpoint.
A system similar to the Renee system is shown in U.S. Pat. No. 5,476,132 issued to Jacobson only in this system, there are two helical wands with controlling elements slidable along the length of the wands to operate the system. This patent, of course, compounds the expense and aesthetic problems mentioned in connection with the Renee system.
Swedish Patent No. 153,833 issued to Bierlich discloses still another system for rotating a wand wherein a portion of the wand has been twisted to form helical surfaces and an outer tube is longitudinally slidable relative to the twisted wand. The outer tube has an interior partition with a square opening therethrough so that as the helical surface of the wand is advanced through the square opening the wand is forced to rotate relative to the outer tube which is held by an operator and slid axially of the twisted wand. This device has the disadvantage of requiring a pitch on the helically twisted rod that is very steep in order to make the device operate with a reasonable sliding force thereby requiring a number of reciprocating asses of the tube relative to the wand in order to affect an operation of the device. It further as a complex and thus expensive gear and brake mechanism to facilitate its operation.
It is to provide a device that makes a wand easy to manipulate and that overcomes the shortcomings in the prior art that the present invention has been developed.